It is often necessary to quickly obtain a sample of blood and perform an analysis of the blood sample. One example of a need for quickly obtaining a sample of blood is in connection with a blood glucose monitoring system where a user must frequently use the system to monitor the user's blood glucose level.
Those who have irregular blood glucose concentration levels are medically required to self-monitor their blood glucose concentration level. An irregular blood glucose level can be brought on by a variety of reasons including illness, such as diabetes. The purpose of monitoring the blood glucose concentration level is to determine the blood glucose concentration level and then to take corrective action, based upon whether the level is too high or too low, to bring the level back within a normal range. The failure to take corrective action can have serious implications. When blood glucose levels drop too low, a condition known as hypoglycemia, a person can become nervous, shaky, and confused. That person's judgment may become impaired and that person may eventually pass out. A person can also become very ill if their blood glucose level becomes too high, a condition known as hyperglycemia. Both conditions, hypoglycemia and hyperglycemia, are potentially life-threatening emergencies.
One method of monitoring a person's blood glucose level is with a portable, hand-held blood glucose testing device. A prior art blood glucose testing device 100 is illustrated in FIG. 1. The portable nature of these devices 100 enables the users to conveniently test their blood glucose levels wherever the user may be. The glucose testing device contains a test sensor 102 to harvest the blood for analysis. The device 100 contains a switch 104 to activate the device 100 and a display 106 to display the blood glucose analysis results. In order to check the blood glucose level, a drop of blood is obtained from the fingertip using a lancing device. A prior art lancing device 120 is illustrated in FIG. 2. The lancing device 120 contains a needle lance 122 to puncture the skin. Some lancing devices implement a vacuum to facilitate drawing blood. Once the requisite amount of blood is produced on the fingertip, the blood is harvested using the test sensor 102. The test sensor 102, which is inserted into a testing unit 100, is brought into contact with the blood drop. The test sensor 102 draws the blood to the inside of the test unit 100, which then determines the concentration of glucose in the blood. Once the results of the test are displayed on the display 106 of the test unit 100, the test sensor 102 is discarded. Each new test requires a new test sensor 102.
One problem associated with some conventional test sensors is that the proper amount of blood may not be obtained. The test sensor used needs a minimum amount of blood to provide accurate results. If the proper amount of blood is not received, inaccurate results may be generated.
Another problem associated with some conventional test sensors is that the user cannot ensure that the proper amount of blood has been obtained. The user applies the blood directly onto a read area and then obtains a reading from the device. If an unusual reading is given, the user may surmise that the unusual reading was caused by an improper amount of blood being obtained. The user may then try again. There is no way for the user to know, however, if that is the true reason for the unusual result.
Another problem associated with some conventional test sensors is the presence of air gaps in the blood sample that is being read. Air gaps in the blood sample can also cause inaccurate readings, requiring the user to retest.
Another problem associated with some conventional test sensors is that the user's blood physically contacts the elements within the testing unit. Cross-contamination can be a problem if the monitoring device is used by more than one user, such as in a doctor's office or other clinical setting.